JPS6263453A - Semiconductor device - Google Patents

Abstract

PURPOSE:To reduce stress in a sealing resin without impairing reliability and to cope with the implementation of a large semiconductor device, by using a specified epoxy resin composition, and sealing a semiconductor element. CONSTITUTION:An epoxy resin composition is obtained by using at least one component, which is selected in groups comprising the following components: an epoxy resin (A component); a phenol resin (B component); polydimethylsiloxane oligomer (C component), which has at least one first- or secondary amino group in a molecule; an addition reaction product (D component) of C component and a monoepoxy compound expressed by the Formula 1; and an addition reaction product (E component) of the C component, the monoepoxy compound expressed by the Formula 1 and a bisphenol A type epoxy resin. In the semiconductor device obtained in this way, inner stress in the hardened body of the epoxy resin composition is low. Therefore, the device has very excellent electric characteristics and low stress property.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor device with superior reliability.

[Conventional technology]

Semiconductor elements such as transistors, ICs, and LSIs are usually sealed with ceramic packages, plastic packages, or the like to form semiconductor devices. The above-mentioned ceramic package has heat resistance in the constituent material itself,
It also has excellent moisture permeability, so it is resistant to temperature and humidity, and because it is a hollow package, it has high mechanical strength and can be sealed with high reliability. However, since the constituent materials are relatively expensive and the mass productivity is poor, resin sealing using the above-mentioned plastic package has recently become mainstream.

Recently, due to technological innovation in the semiconductor field, the degree of integration has improved, element sizes have become larger, and wiring has become finer. stress.

There is a strong demand for improvements in moisture resistance reliability, shock resistance reliability, heat resistance reliability, etc.), and in particular, there is a strong demand for semiconductor encapsulation resins to have the property that the stress applied to semiconductor elements is small even when directly molded. has been done. As a resin for semiconductor encapsulation,
Epoxy resin compositions containing an epoxy resin, a novolak type phenolic resin 2, an inorganic filler as main components, and further containing a curing accelerator, a coloring agent, and a mold release agent have been widely used.

However, when semiconductor elements are molded with this type of encapsulating resin, the stress of the resin can cause cracks in the passivation film or the element itself, or misalignment in the aluminum wiring, which has rarely been a problem. I've come to understand. This becomes more noticeable as the dimensions of the element itself become larger.

Therefore, as a countermeasure to this problem, the development of a resin that applies less stress to the element (low-stress resin) has become a major issue today. As a method for achieving this objective, it is possible to make the epoxy resin or phenol resin itself flexible or to add a plasticizer.

However, in the case of an epoxy resin composition using a phenol resin as a curing agent, the glass transition point of the cured resin is lowered and the high-temperature electrical properties are lowered, so there is a problem in terms of reliability. It is also possible to reduce the stress applied to the element by adding synthetic rubber, etc., but adding synthetic rubber may reduce the adhesion of the resin composition to the semiconductor element and lead frame. , moisture resistance deteriorates and reliability decreases.

[Problem that the invention seeks to solve]

As mentioned above, conventional encapsulating resins have not been satisfactory in terms of stress on semiconductor elements;
In order to cope with the increase in element size caused by the above-mentioned technological innovations, further improvement in characteristics is strongly desired.

This invention was made in view of the above circumstances, and its purpose is to reduce the stress of a sealing resin without impairing its reliability, thereby making it possible to cope with the increase in the size of semiconductor devices. It is something.

[Means for solving problems]

In order to achieve the above object, the semiconductor device of the present invention includes:
Contains the following components (A) and (B), and further contains (C
), (D), and (E) components.

(A) Epoxy resin.

(B) Phenol resin.

(C) A polydimethylsiloxane oligomer having at least one primary or secondary amino group in the molecule.

(D> Addition reaction product of a polydimethylsiloxane oligomer having at least one primary or secondary amino group in the molecule and a monoepoxy compound represented by the following general formula (1).

(E) A polydimethylsiloxane oligomer having at least one primary or secondary amino group in the molecule, a monoepoxy compound represented by the above general formula (1), and a bisphenol A type epoxy resin. addition reaction product.

As mentioned above, the epoxy resin composition used in this invention contains an epoxy resin (component A), a phenolic resin (component B), and at least one member selected from the group consisting of the above-mentioned components C, D, and E. It is obtained using two ingredients and is usually in powder form or tablet form. In addition, the above-mentioned "oligomer" is used to include dimers.

The epoxy resin serving as the component A is not particularly limited, and various epoxy resins conventionally used as sealing resins for semiconductor devices, such as cresol novolac type, phenol novolac type, and bisphenol A type, can be mentioned. Among these resins, it is preferable to use one that has a melting point above room temperature and is in the form of a solid or highly viscous solution at room temperature. As a novolak type epoxy resin, usually epoxy ff1160~
250. Those having a softening point of 50 to 130° C. are used, and the Talesol novolac type epoxy resin has a softening point of 1-iso to 210° C. per epoxy. Those having a softening point of 60 to 110°C are generally used.

The phenol resin of component B used together with the above epoxy resin acts as a curing agent for the above epoxy resin, and includes phenol novolak, 0-cresol novolak, m-cresol novolak, p-cresol novolak, and 0-ethylphenol novolak. , m-ethylphenol novolak, p-ethylphenol novolak, etc. are preferably used. These novolak resins are
It is preferable to use one having a softening point of 50 to 110°C and a hydroxyl equivalent of 70 to 150.

As for the polydimethylsiloxane oligomer having at least one amino group in the molecule, which is the above component C, for example, both ends of the molecular chain schematically represented by (a) 2 below are primary amino groups. The following is a schematic diagram (
(b) Examples include those containing an amino group as a pendant represented by the formula.

(The following is a blank space) 11□N Nl2 As these polydimethylsiloxane oligomers, commonly used ones can be widely used regardless of molecular weight, viscosity, etc. As an example, the following general formula (
The following can be mentioned.

In addition, a pendant type polydimethylsiloxane oligomer in which the methyl groups of the oligomer are partially substituted with the following substituents is also suitable.

[However, X, /y = 3/1 to 500/1) In the above polydimethylsiloxane oligomer (component C), the amino group present in the molecule easily reacts with the epoxy group, so the component C is mixed with the component A and When mixed with component B to form an epoxy resin composition and sealed with resin, it is fixed between epoxy groups. Therefore, it does not exist in a free state and deteriorate the electrical properties of the cured epoxy resin.

Such a polydimethylsiloxane oligomer can be obtained by a known method. For example, for the type represented by the general formula (c) above, an aminopropyl-terminated disiloxane (the chemical structural formula is as shown in formula (1) below) is prepared, and a cyclic tetradimethylsiloxane (the chemical structure is shown in the formula (1) below) is prepared. (■)
), an aminopropyl (primary amine)-terminated polydimethylsiloxane oligomer (formula (
%Formula% Hff CH.

Moreover, the type represented by the above general formula (d) can also be obtained by a known method.

Synthesis methods for these polydimethylsiloxane oligomers are described in many literatures, but a representative one is Epoxy Resin Chemistry n, edited by R.S. Bauer, ACS Symposium Series, AC3 ( 1983) P21-54 (Epox
y ResinChemistry II, AC5Sy
mposium-5erfes) and is explained in detail.

In this invention, as the polydimethylsiloxane oligomer of component C, it is of course possible to use the aminopropyl-terminated disiloxane represented by the formula (I) as is.

It is desirable that such a polydimethylsiloxane oligomer has a number average molecular radius of 15,000 or less.

The addition reaction product of the above components is obtained by the addition reaction product of the above component C and the monoepoxy compound represented by the general formula (I). Component C is as described above, and representative examples of monoepoxy compounds include the following compounds. Phenoxyethyl glycidyl ether, phenoxytetraethoxyethyl glycidyl ether, phenoxypentaethoxyethyl glycidyl ether 1n-butoxypentaethoxyethyl glycidyl ether. The addition reaction between component C and the monoepoxy compound can be carried out by mixing the two and heating the mixture to a predetermined temperature according to a conventionally known method. That is, the reaction temperature is generally 50 to 200°C, more preferably 80 to 180°C, and the reaction time is appropriately selected in the range of several minutes to several tens of hours depending on the reaction components. In this case, the mutual ratio of the polydimethylsiloxane oligomer, which is the C component, and the monoepoxy compound is as follows: [equivalent of epoxy group in monoepoxy compound Th]/[equivalent of hydrogen in amino group of polydimethylsiloxane] It is preferable to set it to 0.1/1 to 1/1. In other words, the current ratio is 0.1 /
If the ratio is less than 1, the dispersibility in mixing with the epoxy resin will not be sufficient, whereas if the equivalent ratio is larger than 1/1, the epoxy groups will be excessive and the heat resistance of the cured resin will decrease.

The addition reaction product of component E is obtained by addition reaction of the polydimethylsiloxane oligomer (component C), a monoepoxy compound, and a bisphenol A epoxy resin.

The above-mentioned polydimethylsiloxane oligomer and monoepoxy compound are as already explained, and the bisphenol A type epoxy resin used is a conventionally known one,
The addition reaction is also carried out in exactly the same manner as for the above-mentioned components. In this case, the blending ratio of the above three raw materials is [equivalent of epoxy group in monoepoxy compound] + [equivalent of epoxy group in bisphenol A epoxy resin] / [hydrogen of amino group in polydimethylsiloxane oligomer] [equivalent] ratio is o
, l/i to 1/1. That is, if the equivalent ratio is less than 0.1/1, the dispersibility of the mixture with the epoxy resin described below will not be sufficient, and on the other hand, if the equivalent ratio is more than 1/1, the epoxy groups will be excessive and the resin will be This is because the heat resistance of

The above polydimethylsiloxane oligomer (component C) is
Epoxy resin composition excluding filler components [A+B+ (C
, D, E)] 0.5-50%
(hereinafter abbreviated as "%") is desirable. In other words, if the content is outside the above range,
This is because a sufficient stress reduction effect cannot be obtained, and the moisture resistance, electrical properties, etc. of the semiconductor device tend to deteriorate.

In addition, it is preferable to use 3 to 30 parts of the addition reaction product of the above-mentioned components based on 100 parts by weight (hereinafter abbreviated as "parts") of the epoxy resin that is component A, in terms of the effect on reducing stress. . Similarly, the addition reaction product of the component E is also added in an amount of 3 to 30 parts per 100 parts of the epoxy resin that is the component A.
It is preferable to use less than 100% of the total amount of carbon dioxide in terms of the effect of reducing stress.

In addition, in addition to the above raw materials, a curing accelerator may be used if necessary. Suitable examples of the curing accelerator include the following tertiary amines, quaternary ammonium salts, imidazoles, and boron compounds, which may be used alone or in combination.

Tertiary amine triethanolamine, tetramethylhexanediamine, triethylenediamine, dimethylaniline, dimethylaminoethanol, diethylaminoethanol, 2,4
．． 6-) IJs(dimethylaminomethyl)phenol,
N, No-dimethylpiperazine, pyridine, picoline,
1,8-diaza-bicyclo(5,4,0)undecene-
7. Benzyldimethylamine, 2-(dimethylaminomethyl)phenol quaternary ammonium salt dodecyltrimethylammonium chloride, cetyltrimethylammonium chloride, benzyldimethyltetradecylammonium chloride, stearyltrimethylammonium chloride imidazoles 2-methylimidazole, 2-undecyl Imidazole, 2-ethylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole boron compounds, phosphorus compounds tetraphenylboron salts such as triethyleneamine tetraphenylborate, N-methylmorpholine tetraphenylborate , tetraphosphonium tetraphenylborate, triphenylphosphine. In addition to the above raw materials, inorganic fillers, antimony trioxide, flame retardants such as phosphorus compounds, pigments,
Coupling agents such as silane coupling agents, stearic acid and its metal salts.

A mold release agent such as wax can be used. The inorganic filler is not particularly limited (generally used quartz glass powder, talc, silica powder, alumina powder, clay, calcium carbonate, zirconium oxide, zirconium silicate, beryllium oxide, etc.) can be used as appropriate.

The epoxy resin composition used in this invention can be produced, for example, as follows. That is, the above A-
Ingredient E and other additives such as inorganic fillers, pigments, coupling agents, etc. are appropriately blended, and this mixture is kneaded in a heated state using a kneading machine such as a mixing roll machine to melt and mix. The desired epoxy resin composition can be obtained through a series of steps of cooling the mixture, pulverizing it by known means, and, if necessary, compressing it into tablets.

Regarding C-E components, it is not necessary to blend all of them into the epoxy resin composition, and ■C component, D component,
Any one of E component, or ■C+D component, C+E
Components, D→E components, etc. can be combined in combination.

Sealing of a semiconductor element using such an epoxy resin composition is not particularly limited, and can be performed by a conventional method, for example, a known molding method such as transfer molding.

The semiconductor device thus obtained has extremely excellent electrical properties and low stress properties because the cured product of the epoxy resin composition has low internal stress. This low stress property is due to the C component and D component mentioned above.

This is thought to be based on the fact that the 5i-0-5i bonding moiety derived from the polydimethylsiloxane oligomer constituting component E is introduced into the molecular skeleton of the cured resin.

[Effects of the Invention] The semiconductor device of the present invention uses a special epoxy resin composition containing a polydimethylsiloxane oligomer having at least one primary or secondary amino group in the molecule and/or an addition reaction product thereof. It is sealed using
The sealed plastic package is different from conventional epoxy resin compositions, so it has low internal stress.
It also has excellent electrical characteristics and is extremely reliable. In particular, by sealing with the above-mentioned special epoxy resin composition, high reliability as described above can be achieved in large semiconductor devices with 8 pins or more, especially 16 pins or more, or chips with long sides of 4 or more. This is a major feature.

Next, examples will be described.

First, components C to E were prepared as follows.

Preparation of Component C> Six types of polydimethylsiloxane oligomers shown in Table 1 were prepared as component C.

(Leave below) Preparation of component D> Into a flask equipped with a stirrer, a thermometer, and a reflux condenser, 100 parts of the above C■ and 10 parts of phenoxytetraethoxyethyl glycidyl ether were charged, and the mixture was heated for 150 minutes under a nitrogen gas stream. By proceeding with the reaction for 8 hours at °C, a transparent high viscosity liquid D■, which is an addition reaction product, was obtained.

In addition, C■ is used in place of the above C■, and C■ is mixed with 100 parts of phenoxyjethoxyethyl glycol/dyl ether 15
The reaction was continued at 150° C. for 20 hours under a nitrogen gas stream and while refluxing dioxane to obtain another addition reaction product, a transparent high-viscosity liquid D■.

Furthermore, instead of C■ above, use C■, and set C■ to 100
Part and phenoxyjethoxyethyl glycidyl ether 2
0 parts were added, and the reaction was allowed to proceed for 10 hours at 150° C. under a nitrogen gas flow, to obtain another addition reaction product, a transparent high-viscosity liquid D■.

Preparation of Component E> After obtaining the addition reaction product D1 in exactly the same manner as in the preparation of D above, this reaction product was treated with Epicoat 828 (Shell Chemical Co., Ltd.'JJ, bisphenol A type epoxy resin, epoxy equivalent: 184~ 194) 2; Add 9 parts,
The reaction was further continued at 150°C for 5 hours to obtain a viscous addition reaction product E■.

Further, after obtaining addition reaction product D3 in exactly the same manner as in the preparation of D
(manufactured by Shell Chemical Co., Ltd., bisphenol A type epoxy resin, epoxy equivalent: 875-975) was added, and the reaction was further allowed to proceed at 150° C. for 5 hours to obtain another addition reaction product E2.

[Examples 1 to 15] Epoxy resin compositions were prepared in the following manner using the components C to E which were half-coated as described above. That is, epoxy paddle fat is melted by placing it in a stirring mixer heated to 150 to 160°C, and according to Table 2 below, the above C-
Component E was added and stirred for 60 minutes. Then, this mixed melt is taken out into a vat, etc., cooled and solidified, and then pulverized into particles of 111 or less. Next, this pulverized material and other raw materials are blended according to Table 2, and mixed using a mixing roll machine (roll temperature 80~
Melt and knead at 90°C for 10 minutes, cool and solidify, then crush.
The desired powdered epoxy resin composition was obtained.

(The following is a blank space) [Conventional example] Using the raw materials shown in Table 3 below, these raw materials were kneaded for 10 minutes with a mixing roll machine, and the obtained sheet-like composition was used in the same manner as in Examples 1 to 14. A powdered epoxy resin composition was obtained.

*1, *2: Semiconductor devices were obtained by molding semiconductor elements by transfer molding using the powdered epoxy resin compositions obtained in the above examples and conventional examples as shown in Table 2. Regarding the semiconductor device obtained in this way, internal stress due to piezo resistance 2 bending elastic modulus, -50°C 15 minutes to 150°C
Temperature cycle test of 2000 times for 15 minutes at °C (rT
CT test (abbreviated as “CT test”) was performed. The results are shown in Table 4 below. Note that the glass transition temperature (Tg) is the temperature at which the peak of Tan δ, which is a viscoelastic property, is reached.

(The following is a margin.) From the results in Table 4, it can be seen that the internal stress of the plastic package is smaller than that of the conventional product, and the results of the TCT test are also good.

The presence of polydimethylsiloxane oligomers in the epoxy resin composition measured can be confirmed by infrared absorption spectroscopy (IR) analysis.

Claims (1)

[Claims] (1) An epoxy resin composition containing the following components (A) and (B), and further containing at least one component selected from the group consisting of components (C), (D), and (E). A semiconductor device that uses a material to seal a semiconductor element. (A) Epoxy resin. (B) Phenol resin. (C) A polydimethylsiloxane oligomer having at least one primary or secondary amino group in the molecule. (D) An addition reaction product of a polydimethylsiloxane oligomer having at least one primary or secondary amino group in the molecule and a monoepoxy compound represented by the following general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) In formula (1), R represents an alkyl group or an aryl group, and n represents an integer from 1 to 10. (E) A polydimethylsiloxane oligomer having at least one primary or secondary amino group in the molecule, a monoepoxy compound represented by the above general formula (1), and a bisphenol A type epoxy resin. Addition reaction product.